Most known speakers have a configuration such that a cone-type diaphragm is supported at its periphery by a metal speaker frame through an edge, and one end of a bobbin, having a voice coil previously wound thereon, is adhesively fixed to the diaphragm at its inner periphery. The diaphragm, & etc. are attached to a separately assembled driver unit constituted by a center pole, a yoke, a magnet, and a top plate so that the voice coil is located in an air gap of the driver unit, and a damper for supporting the bobbin is fixed to the speaker frame.
Such a speaker is generally assembled with seven or eight pieces, and those constituent members are manufactured in various manufacturing steps which are different from each other. For example, a diaphragm is obtained by paper-molding of a pipe material, an edge is obtained through plastic working on a cloth base coated with a filling-up material or the like, and a speaker frame is molded through pressing or casting.
Such speakers as described above have problems in that constituent members manufactured in separate manufacturing steps respectively are assembled in a predetermined order, so that separate steps equal in number to the constituent members are required. The number of such constituent parts is large, and the cost is high because of the complexity in operation and control.